Sprint Nextel is welcoming iPhone users to its network by extending its unlimited data plans to them.

iPhone users on Sprint’s network will be able to get unlimited data and text, plus 450 voice minutes, for $69.99 a month and a $10 a month "premium data add-on charge."

If 450 minutes isn’t enough, there’s a 900-minute plan that costs $89.99 a month or an unlimited voice plan for $99.99 a month.

A mobile hotspot option, which will support up to five WiFi devices, is also available for an additional $29.99 per month, plus taxes and surcharges.

Apple officially anointed Sprint as an iPhone carrier at the unveiling of the iPhone 4S. Sprint reportedly agreed to buy 30.5 million iPhones from Apple over the next three years to bring the smartphone into its lineup.

“Our unlimited data plans are the perfect fit for iPhone customers,” Sprint chief executive Dan Hesse said in a statement. “Sprint’s unlimited data plans provide more value than metered plans from other carriers. Our customers can take advantage of the innovative features of iPhone without worrying about overage charges or surprises on their bill."

Verizon and AT&T both tried offering unlimited data plans to their smartphone customers but have adopted tiered systems that set flat rates and ceilings on data usage. AT&T, for instance, charges $25 a month for 2GB of data and $10 for every gigabyte of data above that threshold.

Asked by All Things D if Sprint's network could handle the load unlimited data would place on it, company spokeswoman Michelle Leff Mermelstein said: "We have every confidence in the ability of our 3G network to handle the influx of devices we expect to get. It certainly hasn’t been an issue to date."

Pricing for the iPhone 4S is $199.99 for the 16GB model, $299.99 for the 32GB edition and $399.99 for the 64GB version.

Sprint also announced that it began selling the iPhone 4 for $99.99 through its website. Sprint, Verizon and AT&T all sell the iPhone 4 and iPhone 4S, while AT&T also offers the older iPhone 3GS for free with a two-year contract.

Sprint's new iPhone users will have access to the company's Ready Now service, which gives them access to sales associates who can work one-on-one with a user to set up their e-mail, Web access and apps before leaving a Sprint store.